The invention relates to a hydraulic valve for an oscillating motor adjuster that utilizes camshaft alternating torques by means of non-return valves for more rapid adjustment.
An oscillating motor adjuster having a hydraulic valve with which camshaft alternating torques can be utilized for more rapid adjustment is already known from DE 10 2006 012 733 B4 and DE 10 2006 012 775 B4. For this purpose, pressure peaks caused by camshaft alternating torques are conducted from each of the pressure chambers of the oscillating motor adjuster to be discharged via a non-return valve into the flow of the oil pump. Thus, additional volume is provided for the pressure chamber to be filled, in addition to the normal flow volume of the oil pump. In order to make possible a more rapid adjustment in both oscillating directions, a non-return valve is provided for each of the oscillating directions. Structurally, the hydraulic valve has two working ports for this purpose. These two working ports each have a standard port part axially adjacent to one another and a port part for utilizing pressure peaks as a consequence of camshaft alternating torques. The hydraulic pressure can be introduced from a supply port to the working port that is to be loaded, whereas the working port that is to be relieved of pressure is guided to a tank port.
In order to also maintain the adjusting capacity in the case of internal combustion engines with very greatly fluctuating camshaft alternating torques, DE 10 2010 014 500.9, which has not been pre-published, proposes that one switching position of the hydraulic valve can be controlled proportionally, in which the pressure peaks of the working port to be relieved of pressure are blocked relative to the supply port and the working port that is to be loaded.
DE 102 11 467 A1 relates to a central valve that takes over the function of a so-called central screw and clamps the rotor against the camshaft. Thus, as a disadvantage, stresses occur in the hydraulic valve.
A hydraulic valve for an oscillating motor adjuster is already known from EP 1 476 642 B1, which has two hollow pistons that support each other via a flat spiral spring. A gap can be opened and closed therewith between the two pistons.
The problem to be solved by the present invention is to create an oscillating motor adjuster that has a high adjusting capacity despite a high adjusting speed with a low oil pump pressure.